During an investigation, a scientist heated 123.6 g of copper carbonate till it decomposed to form a black residue. The total mass of the black residue formed was 79.6 g. Does the law of conservation of mass hold true in this case?

Which type of simple machine reduces the amount of input force needed?

The lava lamp has a light bulb as a heat source at its base. The lamp contains a colored, waxy fluid that can be observed moving in clumps through a clear liquid.

What would most likely happen if one of the runners bagan jogging in knee-deep water

Two trains start from towns 224 mi apart and travel towards each other on parallel tracks. They pass each other 1.6 hr later. If one train travels 10 mph faster than the other, find the speed of each train.

The diagram shows two bar magnets. They are cut along the dashed line, and then the two marked ends are placed near each other. Two bar magnet horizontal. The top has the north pole left and the south pole right. The magnet below is reversed.

With your bare feet, stand with one foot on a rug, and the other foot on a tile, linoleum, or wood floor. Which one feels colder? Which one is really colder? Explain what is going on in a paragraph.

A firewoman dropped a person onto the safety net. Right before the person hit the net he had a velocity of 11.2 m/s and 1800 J of kinetic energy. What was the mass of the person?

What causes standing wave?

If you lived downhill from a volcano and lava started to flow toward your home what could happen?

A battleship simultaneously fires two shells toward two identical enemy ships. One shell hits ship A, which is close by, and the other hits ship B, which is farther away. The two shells are fired at the same speed.